Brazing cutting tools

At this time, the weld is subjected to compressive stress while the surface of carbide brazed tool is subjected to tensile stress. If the residual stress is greater than the requirement of tensile strength or crack resistance of cemented carbide, cracks may occur on the surface of cemented carbide, which is one of the main causes of cracks in carbide brazed tool brazing. Residual stress in welded joint area is a potential hazard. Although cracks may not be found immediately after brazing, they are prone to occur during subsequent grinding, storage or use, resulting in tool scrap.

The larger the brazing area of cemented carbide, the greater the brazing stress and the greater the possibility of cracking. In the brazing of carbide brazed tool tools, measures must be taken to minimize the brazing stress, such as reducing the brazing temperature, preheating and slowly cooling before brazing, choosing plastic filler metal, adding compensating gaskets and improving joint structure.

Brazing large area cemented carbide. Special measures should be taken to reduce brazing stress and prevent crack production, regardless of strength. When the carbide brazed tool is heated to more than degrees Celsius in air, the surface of the carbide brazed tool begins to oxidize to form a loose oxide layer, accompanied by decarburization phenomenon. When heated to degrees Celsius to degrees Celsius, the surface layer of the carbide brazed tool will undergo rapid oxidation, which can reduce the mechanical properties of the cemented carbide.

Oxidation film. The existence of oxide layer on the surface of carbide brazed tool also reduces the hardness of the weld. Therefore, measures should be taken to minimize the oxidation phenomenon in the brazing parts of cemented carbide, which is an important measure to improve the brazing quality.

The main brazing methods of carbide brazed tool and steel are oxygen-acetylene flame brazing, high frequency induction brazing, contact resistance brazing, and brazing in heating furnace.

This is one of the most commonly used brazing methods. High-quality carbide brazed tool can be welded by using reasonable heating method and proper process according to the characteristics of oxygen-acetylene flame.

Oxygen-acetylene flame brazing is suitable for small and medium-sized carbide brazed tool cutting tools, dies and measuring tools in batches, and also for repairing damaged carbide brazed tool mining tools in the field. The core temperature of oxygen-acetylene flame is as high as about C.

When brazing is heated, it should be avoided to spray carbide brazed tool directly from the core, so as to avoid cracking caused by excessive temperature. Before brazing, the filler metal, filler metal and carbide brazed tool are placed in turn, and the reduction flame is used to preheat the base part near the cemented carbide. In high frequency induction brazing, high frequency induction heating power supply with frequency of kHz and power between 10 and kW will generate high frequency current.

When the high frequency current passes through the inductor, the high frequency alternating magnetic field is generated, and the induced current is also generated in the welded metal of the inductor.

The high frequency heating speed is very fast. Item :. Locate Wholesaler. Select to Compare. Sil-Fos Brazing Alloys. See Full Product Details. Primarily joins nickel and iron base alloys Can Use to join other non-ferrous metals Nickel content enhances wetting Very fluid at brazing temperature Blocks interface corrosion on stainless steel Cadmium free Made in USA. High Silver Brazing Alloys. Primarily joins nickel and iron base alloys Coated with general purpose Handy Flux Improved joint strength due to less flux inclusion Minimizes post-braze cleaning Reduces brazing cycle times Made in USA.

The main advantages of brazing alloy are low cost and high welding strength. However, the disadvantages are: the temperature of brazing spot is high, generally above e, and the weld stress is large. The advantages of silver solder are: good technical performance, low melting point, good wettability, ability to fill gaps, good strength and plasticity. Its disadvantages are: high price, low operating temperature of brazed joint.

The size of brazing weld gap is a key factor affecting the density and strength of brazing weld. Too small gap hinders the inflow of brazing solder and too large gap damages the capillary action of brazing weld and makes brazing solder unable to fill the gap. Brazing of cutting tool, it is steel and carbide brazing of dissimilar materials, considering the linear expansion coefficient of carbide smaller than steel, so the brazing seam clearance should be smaller than when steel on steel welding, when using HL, HL copper solder, cutting tool brazing gap generally 0.

Conclusion In summary, due to its high production efficiency and stable quality of the brazing joint, the vacuum brazing and quenching of the cutting tool can be heated, brazed and cooled completely in the vacuum environment to avoid oxidation and decarbonization of the cutting tool.

Therefore, the vacuum brazing and quenching process of cutting tool will be more and more widely used. Please send us your inquiry about the customization of other furnace types or related questions about vacuum furnace. We will reply you immediately.

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